Over past decades, mobile telecommunications networks have become the primary solution also in the growing markets. Inexpensive to deploy and yet capable to host significant amounts of subscribers, mobile telecommunications networks are connecting ever increasing amounts of cities, towns and villages. However, as mobile telecommunications networks are built to developing markets, an increasing portion of potential users is unable to purchase a personal mobile telephone. When needed users may borrow or rent a phone from a friend, relative or kiosk, for example. Of course, the borrower should cover the subscription charging incurred by her use. To this end, there are particular pre-paid subscriptions associated with a predetermined balance on a charging account and possibly capable of being topped up. The topping up may take place by using a dedicated machine or even by using a scratch card as described in WO2004059964A1 assigned to the patentee of this patent application.
If a mobile phone is lent to a borrower, the lender should remove her Subscription Identity Module (SIM) to prevent the borrower from using it. Typically, this means that at least the battery of the phone has to be detached to access the SIM and often a cover should be detached before the battery can be accessed and detached. The feature that the battery should cover the SIM or somehow inhibit detaching of the SIM while the phone is switched on may be partly caused by the need to protect the SIM as the mobile telephones are not generally designed such that the SIM could be safely detached anytime. Further, the detached SIM should be preserved over the period the mobile telephone is lent such that its contacts would not become dirty or greasy. The mobile telephone is also subjected to two SIM removals and insertions each time the mobile telephone is lent and the lender's SIM has to be re-inserted before the operability of the mobile telephone can be tested as otherwise the phone typically stops on starting to prompt “Insert SIM”. Finally, the pre-paid subscriptions may simply be unsuitably expensive for the borrower or their topping up inaccessible at the moment the phone should be lent. Hence, there is a need for facilitating the lending of a telephone subscription to a borrower.
It could be useful to build an application that would control the use of the mobile phone based on network provided charging information such that the use could be restricted according to particular limits. GSM Advice of Charge (AoC) supplementary services, for instance, allow the tariff for a call to be indicated to the mobile phone. This information could be used to calculate the cost of the call and therefore disconnect the call internally when the limit is reached. However, the calculation of call duration in the phone is different from the calculation in the network leading to differences in the actual amount charged to the subscriber and the cost of the call as determined by the phone. The AoC also has limitations in terms of how the tariffs are defined and which services tariffs can be provided for.
It is an object of the invention to avoid or at least to mitigate present problems.